okay--i understand that now, in basic terms: "may be considered prions". But, looking a bit further, since most animals are not fed naturally (and may be ingesting antibiotics, hormones, who-knows-what-we-don't know; and "animal-by-products": ie. their own kind) I believe the really dangerous prions (and much is not known yet about this) are coming from meat. I know most people on this forum now eat 'grass-fed' or organic or that sort of thing, if they do eat meat. But so many don't...it's a scary concept.